In-band full-duplex operation

ABSTRACT

In some aspects, the disclosure is directed to methods and systems for in-band full-duplex operation. A first device transmits a frame to a second device wirelessly within a first frequency band, in one or more embodiments. In one or more embodiments, the first device detects, while the transmission of the frame is ongoing, feedback from the second device within the first frequency band. In one or more embodiments, the feedback is in response to the ongoing transmission of the frame. In one or more embodiments, the first device determines, responsive to the feedback, whether to stop the ongoing transmission of the frame or to update a transmission parameter for the ongoing transmission within the first frequency band.

RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/073,645, filed Oct. 31, 2014, the entirecontents of which are incorporated herein by reference in their entiretyfor all purposes.

FIELD OF THE DISCLOSURE

This disclosure generally relates to systems and methods for managingtransmission links of a communications system, including but not limitedto systems and methods for full-duplex operation.

BACKGROUND OF THE DISCLOSURE

In the last few decades, the market for wireless communications deviceshas grown by orders of magnitude, fueled by the use of portable devices,and increased connectivity and data transfer between all manners ofdevices. Digital switching techniques have facilitated the large scaledeployment of affordable, easy-to-use wireless communication networks.Furthermore, digital and radio frequency (RF) circuit fabricationimprovements, as well as advances in circuit integration and otheraspects have made wireless equipment smaller, cheaper, and morereliable. Wireless communication is able to operate in accordance withvarious standards such as IEEE 802.11x Bluetooth, global system formobile communications (GSM), code division multiple access (CDMA). Asincreased data throughput and other developments occur, updates and newstandards are constantly being developed fir adoption, such thoseassociated with the third generation partnership project (3GPP) and IEEE802.11.

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects, aspects, features, and advantages of the disclosurewill become more apparent and better understood by referring to thedetailed description taken in conjunction with the accompanyingdrawings, in which like reference characters identify correspondingelements throughout. In the drawings, like reference numbers generallyindicate identical, functionally similar, and/or structurally similarelements.

FIG. 1A is a block diagram depicting an embodiment of a networkenvironment including one or more wireless communication devices incommunication with one or more devices or stations;

FIGS. 1B and 1C are block diagrams depicting embodiments of computingdevices useful in connection with the methods and systems describedherein;

FIG. 2A is a block diagram depicting an embodiment of a system forin-band full-duplex operation;

FIG. 2B is a schematic diagram of embodiments of in-band operation;

FIG. 2C is a schematic diagram of another embodiment of in-bandoperation; and

FIG. 2D is a flow diagram depicting an embodiment of process operationsfor in-band full-duplex operation.

The details of various embodiments of the methods and systems are setforth in the accompanying drawings and the description below.

DETAILED DESCRIPTION

The following standard(s) and specification(s), including any draftversions of such standard(s) and specification(s), are herebyincorporated herein by reference in their entirety and are made part ofthe present disclosure for all purposes: Long-Term Evolution (LTE);LTE-Advanced (LTE-A); 3GPP; and IEEE 802.11. Although this disclosuresometimes reference aspects of these standard(s) and specification(s),the disclosure is in no way limited to these aspects.

For purposes of reading the description of the various embodimentsbelow, the following descriptions of the sections of the specificationand their respective contents could be helpful:

-   -   Section A describes a network environment and computing        environment which could be useful for practicing embodiments        described herein; and    -   Section B describes embodiments of systems and methods in-band        full-duplex operation.

A. Computing and Network Environment

Prior to discussing specific embodiments of the present solution,aspects of the operating environment as well as associated systemcomponents (e.g., hardware elements) are described in connection withthe methods and systems described herein. Referring to FIG. 1A, anembodiment of a network environment is depicted. In brief overview, thenetwork environment includes a wireless communication system thatincludes one or more base stations 106, one or more wirelesscommunication devices 102 and a network hardware component 192. Thewireless communication devices 102 sometimes for example include laptopcomputers 102, tablets 102, personal computers 102 and/or cellulartelephone devices 102. The details of an embodiment of each wirelesscommunication device and/or base station are described in greater detailwith reference to FIGS. 1B and 1C. The network environment is an ad hocnetwork environment, an infrastructure wireless network environment, asubnet environment, etc., in one or more embodiments.

Terms such as “wireless communication device”, “user equipment,” “mobilestation,” “mobile,” “mobile device,” “subscriber station,” “subscriberequipment,” “access terminal,” “terminal,” “handset,” and similarterminology, sometimes refer to a wireless device utilized by asubscriber or user of a wireless communication service to receive orconvey data, control, voice, video, sound, gaming, or substantially anydata-stream or signaling-stream. The foregoing terms can be utilizedinterchangeably in the present disclosure. Likewise, terms such as“access point (AP),” “wireless access point (WAP),” “base station,”“base transceiver station”, “Node B.” “evolved Node B (eNode B or eNB),”home Node B (HNB),” “home access point (HAP),” and similar terminology,can be utilized interchangeably in the present disclosure, and refer toa wireless network component or apparatus that serves and receives data,control, voice, video, sound, gaining, or substantially any data-streamor signaling-stream from a set of wireless devices.

Referring again to FIG. 1A, the base stations 106 is operably coupled tothe network hardware 192 via local area network connections in one ormore embodiments. The network hardware 192, which can include a router,gateway, switch, bridge, modem, system controller, appliance, etc., canprovide a local area network connection for the communication system.Each of the base stations 106 can have an associated antenna or anantenna array to communicate with the wireless communication devices 102in its area. The wireless communication devices 102 can register with aparticular access point 106 to receive services from the communicationsystem (e.g., via a single-user multiple input multiple output—SU-MIMOor multiple-user multiple input multiple output—MU-MIMO, configuration).For direct connections (e.g., point-to-point communications), somewireless communication devices 102 can communicate directly via anallocated channel and communications protocol. Some of the wirelesscommunication devices 102 can be mobile or relatively static withrespect to the access point 106.

In some embodiments, a base station 106 includes a device or module(including a combination of hardware and software) that allows wirelesscommunication devices 102 to connect to a wired network using LTE,Wi-Fi, and/or other standards. A base station 106 can be implemented,designed and/or built for operating in a wireless local area network(WLAN), such as in a cellular network. A base station 106 can connect toa router (e.g., via a wired network) as a standalone device in someembodiments. In other embodiments, a base station can be a component ofa router. A base station 106 can provide multiple devices 102 access toa network. A base station 106 can, for example, connect to a wiredEthernet connection and provide wireless connections using radiofrequency links for other devices 102 to utilize that wired connection.A base station 106 can be built and/or implemented to support a standardfor sending and receiving data using one or more radio frequencies.Those standards and the frequencies they use can be defined by the IEEEor 3GPP for example. A base station 106 can be implemented and/or usedto support cellular coverage, public Internet hotspots, and/or on aninternal network to extend the network's signal (e.g., Wi-Fi) range.

In some embodiments, the base stations 106 can be used for (e.g.,in-home or in-building) wireless networks (e.g., IEEE 802.11, Bluetooth,ZigBee, cellular, any other type of radio frequency based networkprotocol and/or variations thereof). Each of the wireless communicationdevices 102 can include a built-in radio and/or is coupled to a radio.Such wireless communication devices 102 and/or base stations 106 canoperate in accordance with the various aspects of the disclosure aspresented herein to enhance performance, reduce costs and/or size,and/or enhance broadband applications. Each wireless communicationdevices 102 can have the capacity to function as a client node seekingaccess to resources (e.g., data, and connection to networked nodes suchas servers) via one or more base stations 106.

The network connections can include any type and/or form of network andcan include any of the following: a point-to-point network, a broadcastnetwork, a telecommunications network, a data communication network, acomputer network. The topology of the network can be a bus, star, orring network topology. The network can be of any such network topologyas known to those ordinarily skilled in the art capable of supportingthe operations described herein. In some embodiments, different types ofdata can be transmitted via different protocols. In other embodiments,the same types of data can be transmitted via different protocols.

The communications device(s) 102 and base station(s) 106 can be deployedas and/or executed on any type and form of computing device, such as acomputer, network device or appliance capable of communicating on anytype and form of network and performing the operations described herein.FIGS. 1B and 1C depict block diagrams of a computing device 100 usefulfor practicing an embodiment of the wireless communication devices 102or the base station 106. As shown in FIGS. 1B and 1C, each computingdevice 100 includes a central processing unit 121, and a main memoryunit 122. As shown in FIG. 1B, a computing device 100 can include astorage device 128, an installation device 116, a network interface 118,an I/O controller 123, display devices 124 a-124 n, a keyboard 126 and apointing device 127, such as a mouse. The storage device 128 caninclude, without limitation, an operating system and/or software. Asshown in FIG. 1C, each computing device 100 can also include additionaloptional elements, such as a memory port 103, a bridge 170, one or moreinput/output devices 130 a-130 n (generally referred to using referencenumeral 130), and a cache memory 140 in communication with the centralprocessing unit 121.

The central processing unit 121 is any logic circuitry that responds toand processes instructions fetched from the main memory unit 122. Inmany embodiments, the central processing unit 121 is provided by amicroprocessor unit, such as: those manufactured by Intel Corporation ofMountain View, Calif.; those manufactured by International BusinessMachines of White Plains, N.Y.; those manufactured by ARM Holdings, plcof Cambridge, England. or those manufactured by Advanced Micro Devicesof Sunnyvale, Calif. The computing device 100 can be based on any ofthese processors, or any other processor capable of operating asdescribed herein.

Main memory unit 122 can be one or more memory chips capable of storingdata and allowing any storage location to be directly accessed by themicroprocessor 121, such as any type or variant of Static random accessmemory (SRAM), Dynamic random access memory (DRAM), Ferroelectric RAM(FRAM), NAND Flash, NOR Flash and Solid State Drives (SSD). The mainmemory 122 can be based on any of the above described memory chips, orany other available memory chips capable of operating as describedherein. In the embodiment shown in FIG. 1B, the processor 121communicates with main memory 122 via a system bus 150 (described inmore detail below). FIG. 1C depicts an embodiment of a computing device100 in which the processor communicates directly with main memory 122via a memory port 103. For example, in FIG. 1C the main memory 122 canbe DRDRAM.

FIG. 1C depicts an embodiment in which the main processor 121communicates directly with cache memory 140 via a secondary bus,sometimes referred to as a backside bus. In other embodiments, the mainprocessor 121 communicates with cache memory 140 using the system bus150. Cache memory 140 typically has a faster response time than mainmemory 122 and is provided by, for example, SRAM, BSRAM, or EDRAM. Inthe embodiment shown in FIG. 1C, the processor 121 communicates withvarious I/O devices 130 a-n via a local system bus 150. Various busescan be used to connect the central processing unit 121 to any of the I/Odevices 130, for example, a VESA VL bus, an ISA bus, an EISA bus, aMicroChannel Architecture (MCA) bus, a PCI bus, a PCI-X bus, aPCI-Express bus, or a NuBus. For embodiments in which the I/O device isa video display 124, the processor 121 can use an Advanced Graphics Port(AGP) to communicate with the display 124. FIG. 1C depicts an embodimentof a computer 100 in which the main processor 121 can communicatedirectly with I/O device 130 b, for example via HYPERTRANSPORT, RAPIDIO,or INFINIBAND communications technology. FIG. 1C also depicts anembodiment in which local busses and direct communication are mixed: theprocessor 121 communicates with I/O device 130 a using a localinterconnect bus while communicating with I/O device 131 directly.

A wide variety of I/O devices 130 a-n and 131 can be present in thecomputing device 100. Input devices include keyboards, mice, trackpads,trackballs, microphones, dials, touch pads, touch screen, and drawingtablets. Output devices include video displays, speakers, inkjetprinters, laser printers, projectors and dye-sublimation printers. TheI/O devices 130 a-n can be controlled by an I/O controller 123 as shownin FIG. 1B. The I/O controller can control one or more I/O devices suchas a keyboard 126 and a pointing device 127, e.g., a mouse or opticalpen. Furthermore, an I/O device can also provide storage and/or aninstallation medium 116 for the computing device 100. In still otherembodiments, the computing device 100 can provide USB connections (notshown) to receive handheld USB storage devices such as the USB FlashDrive line of devices manufactured by Twintech Industry, Inc. of LosAlamitos, Calif.

Referring again to FIG. 1B, the computing device 100 can support anysuitable installation device 116, such as a disk drive, a CD-ROM drive,a CD-R/RW drive, a DVD-ROM drive, a flash memory drive, tape drives ofvarious formats, USB device, hard-drive, a network interface, or anyother device suitable for installing software and programs. Thecomputing device 100 can further include a storage device, such as oneor more hard disk drives or redundant arrays of independent disks, forstoring an operating system and other related software, and for storingapplication software programs such as any program or software 120 forimplementing (e.g., built and/or designed for) the systems and methodsdescribed herein. Optionally, any of the installation devices 116 couldalso be used as the storage device. Additionally, the operating systemand the software can be run from a bootable medium.

Furthermore, the computing device 100 can include a network interface118 to interface to the network 104 through a variety of connectionsincluding, but not limited to, standard telephone lines, LAN or WANlinks (e.g., 802.11, T1, T3, 56kb, X.25, SNA, DECNET), broadbandconnections (e.g., ISDN, Frame Relay, ATM, Gigabit Ethernet,Ethernet-over-SONET), wireless connections, or some combination of anyor all of the above. Connections can be established using a variety ofcommunication protocols (e.g., TCP/IP, IPX, SPX, NetBIOS, Ethernet,ARCNET, SONET, SDH, Fiber Distributed Data Interface (FDDI), RS232, IEEE802.11, IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, IEEE802.11ac, IEEE 802.11ad, CDMA, GSM, WiMax, LTE, LTE-A and directasynchronous connections). In one embodiment, the computing device 100communicates with other computing devices 100′ via any type and/or formof gateway or tunneling protocol such as Secure Socket Layer (SSL) orTransport Layer Security (TLS). The network interface 118 can include abuilt-in network adapter, network interface card, PCMCIA network card,card bus network adapter, wireless network adapter, USB network adapter,modem or any other device suitable for interfacing the computing device100 to any type of network capable of communication and performing theoperations described herein.

In some embodiments, the computing device 100 can include or beconnected to one or more display devices 124 a-124 n. As such, any ofthe I/O devices 130 a-130 n and/or the I/O controller 123 can includeany type and/or form of suitable hardware, software, or combination ofhardware and software to support, enable or provide for the connectionand use of the display device(s) 124 a-124 n by the computing device100. For example, the computing device 100 can include any type and/orform of video adapter, video card, driver, and/or library to interface,communicate, connect or otherwise use the display device(s) 124 a-124 n.In one embodiment, a video adapter can include multiple connectors tointerface to the display device(s) 124 a-124 n. In other embodiments,the computing device 100 can include multiple video adapters, with eachvideo adapter connected to the display device(s) 124 a-124 n. In someembodiments, any portion of the operating system of the computing device100 can be implemented for using multiple displays 124 a-124 n. Oneordinarily skilled in the art will recognize and appreciate the variousways and embodiments that a computing device 100 can be implemented tohave one or more display devices 124 a-124 n.

In further embodiments, an I/O device 130 a-n can be a bridge betweenthe system bus 150 and an external communication bus, such as a USB bus,an Apple Desktop Bus, an RS-232 serial connection, a SCSI bus, aFireWire bus, a FireWire 800 bus, an Ethernet bus, an AppleTalk bus, aGigabit Ethernet bus, an Asynchronous Transfer Mode bus, a FibreChannelbus, a Serial Attached small computer system interface bus, a USBconnection, or a HDMI bus.

A computing device 100 of the sort depicted in FIGS. 1B and 1C canoperate under the control of an operating system, which controlscheduling of tasks and access to system resources. The computing device100 can be running any operating system such as any of the versions ofthe MICROSOFT WINDOWS operating systems, the different releases of theUnix and Linux operating systems, any version of the MAC OS forMacintosh computers, any embedded operating system, any real-timeoperating system, any open source operating system, any proprietaryoperating system, any operating systems for mobile computing devices, orany other operating system capable of running on the computing deviceand performing the operations described herein. Typical operatingsystems include, but are not limited to: Android, produced by GoogleInc.; WINDOWS 7 and 8, produced by Microsoft Corporation of Redmond,Wash.; MAC OS, produced by Apple Computer of Cupertino, Calif.; WebOS,produced by Research In Motion (RIM); OS/2, produced by InternationalBusiness Machines of Armonk, N.Y.; and Linux, a freely-availableoperating system distributed by Caldera Corp. of Salt Lake City, Utah,or any type and/or form of a Unix operating system, among others.

The computer system 100 can be any workstation, telephone, sensor,desktop computer, laptop or notebook computer, server, handheldcomputer, mobile telephone, or other portable telecommunications device,media playing device, a gaming system, mobile computing device, or anyother type and/or form of computing, telecommunications or media devicethat is capable of communication. The computer system 100 has sufficientprocessor power and memory capacity to perform the operations describedherein.

In some embodiments, the computing device 100 can have differentprocessors, operating systems, and input devices consistent with thedevice. For example, in one embodiment, the computing device 100 is asmart phone, mobile device, tablet or personal digital assistant. Instill other embodiments, the computing device 100 is an Android-basedmobile device, an iPhone smart phone manufactured by Apple Computer ofCupertino, Calif., or a Blackberry or WebOS-based handheld device orsmart phone, such as the devices manufactured by Research In MotionLimited. Moreover, the computing device 100 can be any workstation,desktop computer, laptop or notebook computer, server, handheldcomputer, mobile telephone, any other computer, or other form ofcomputing or telecommunications device that is capable of communicationand that has sufficient processor power and memory capacity to performthe operations described herein.

Aspects of the operating environments and components described abovewill become apparent in the context of the systems and methods disclosedherein.

B. In-Band Full-Duplex Operation

Described herein are systems and methods for in-band full-duplexoperation. In-band full-duplex operation enables simultaneoustransmission (TX) and reception (RX) in the same frequency band, in oneor more embodiments. On the other hand, half-duplex operation providesfor either transmit or receive in a band, but not both, in one or moreembodiments. For example, time division duplex (TDD) systems switchbetween transmitting and receiving, and frequency division duplex (FDD)systems have the capability to simultaneously transmit and receive,using different frequency bands for transmit and for receive, in one ormore embodiments. In one or more embodiments, in-band full-duplexoperation increases system or communications capacity, effectivelydoubling available bandwidth, and therefore potentially doubles theavailable transmission throughput. With respect to TDD systems, the gainis potentially even larger under full-duplex operation, becausehalf-duplex constraint leads to many system inefficiencies, such as atthe media access control (MAC) level in one or more embodiments. Forexample, and in one or more embodiments, a half-duplex TDD system (suchas WLAN) provides a relatively low aggregate throughput when congested,but with full duplex operation, the system potentially avoids congestionand results in a throughput gain that is potentially considerably largerthan two-fold.

In one or more embodiments, under in-band full-duplex operation, adevice's transmitted signal sometimes leaks into the device's receivercircuit (sometimes referred to as “self-interference”). In one or moreembodiments, the signal leakage is at a level that is substantiallyhigher than a received signal-of-interest (e.g., 100 dB stronger). Inone or more embodiments, the self-interference is known to or understoodby the device, because the leakage signal is based on signals generatedand/or transmitted by the device. The use of self-interferencecancellation, based on advances in self-interference cancellation inradio frequency and digital domains, makes in-band operation a viablecommunication solution in one or more embodiments. In one or moreaspects, this disclosure describes some system design implications andsolutions for full-duplex capable devices. For example, under fullduplex operation, a device (e.g., 802.11 or LTE device) has thecapability to receive and transmit at the same time, and therefore canbe designed and/or implemented to provide real time feedback whilereceiving a transmission from another device, in one or moreembodiments. In one or more embodiments, real time feedback allows fordynamic adjustment of transmission parameters based on the feedback.Thus, in one or more embodiments, the use of real time feedbackoptionally or potentially allows for a more aggressive initialmodulation and coding scheme (MCS) to be applied in a transmission forexample.

In one or more embodiments, real time feedback allows devices to addresscollision or transmission priority. In one or more embodiments, suchfeedback is in the form of a confirmation message to indicate that thereceiving device is able to successfully decode the receivedtransmission, and used as a mechanism to address transmissioncollisions. In one or more embodiments, the feedback is implemented toinform a transmission source device to back off its transmission infavor of a higher priority transmission detected within the samefrequency band. In one or more embodiments, to support or facilitatein-band full duplex operation, the devices operate according to rules orprotocol changes that coordinate transmissions across the devices. Forexample, in one or more embodiments, the frame durations of transmit andreceive channels are coordinated. In one or more embodiments, onelink/channel operates at a reduced power relative to another to reduceself-interference for instance. In one or more embodiments, one or moredevices are implemented for frequency-symmetric scheduling toefficiently utilize the band under full duplex operation. One or more ofthe devices optionally learn or receive information about thecharacteristics of various links to adaptively reduce interferencebetween links, in one or more embodiments.

In one or more aspects, the disclosure is directed to embodiments of amethod for in-band full-duplex operation. The method includestransmitting, by a first device, a frame to a second device wirelesslywithin a first frequency band in one or more embodiments. In one or moreembodiments, the first device detects, while the transmission of theframe is ongoing, feedback from the second device within the firstfrequency band. In one or more embodiments, the feedback is in responseto the ongoing transmission of the frame. In one or more embodiments,the first device determines, responsive to the feedback, whether to stopthe ongoing transmission of the frame or to update a transmissionparameter for the ongoing transmission within the first frequency band.

In one or more embodiments, the transmission of the frame andtransmission of the feedback both use an 802.11 or a LTE protocol. Inone or more embodiments, the first device detects a transmission from athird device, and determines to stop, delay or modify the transmissionof the frame based on the detection of the transmission from the thirddevice. In one or more embodiments, the first device detects atransmission from a third device, and determines whether to maintain,stop, delay or modify the transmission of the frame based on a priorityof the transmission from the third device. In one or more embodiments,the first device determines the priority based on at least one or moreof: content, message length, duration, a most recent transmission, orbattery status associated with the transmission from the third device.In one or more embodiments, the feedback includes a sample of thetransmission, or includes information based on a log likelihood ratio(LLR) or decoded bits from the transmission. In one or more embodiments,the first device updates at least one or more of a MCS, code rate, codetype, power, beamforming configuration, number of spatial streams,bandwidth, or sub-band allocation of the transmission responsive to thefeedback.

In one or more aspects, the disclosure is directed to embodiments of amethod for in-band full-duplex operation. The method includes receiving,by a first device, a frame from a second device transmitted wirelesslywithin a first frequency band, in one or more embodiments. In one ormore embodiments, the first device sends, while the transmission of theframe is ongoing, feedback to the second device within the firstfrequency band. In one or more embodiments, the feedback is in responseto the ongoing transmission of the frame. In one or more embodiments,the feedback includes information indicating whether to stop the ongoingtransmission of the frame or to update a transmission parameter for theongoing transmission within the first frequency band.

In one or more embodiments, the first device detects, while thetransmission is ongoing, a transmission from a third device within thefirst frequency band, and sends the feedback based on the detectedtransmission from the third device. In one or more embodiments, thefirst device is one of a wireless local area network (WLAN) device or aLTE device, and the second device is the other of the WLAN device or theLTE device. In one or more embodiments, the first device decodes apreamble of the frame while the transmission is ongoing, and determiningwhether to send the feedback based on the decoding. In one or moreembodiments, the first device sends feedback to the second device atregular intervals while the transmission of the frame is ongoing. In oneor more embodiments, the feedback includes a message transmitted to oneor more devices, the message identifying at least one of the one or moredevices to stop transmission.

In one or more aspects, the disclosure is directed to embodiments of asystem for in-band full-duplex operation. The system includes atransmitter of a first device, the transmitter implemented to wirelesslytransmit a frame to a second device within a first frequency band in oneor more embodiments. In one or more embodiments, a detector of the firstdevice detects, while the transmission of the frame is ongoing, feedbackfrom the second device within the first frequency band, the feedback inresponse to the ongoing transmission of the frame. In one or moreembodiments, a control module of the first device determines, responsiveto the feedback, whether to modify or suspend the ongoing transmissionof the frame within the first frequency band.

In one or more embodiments, the transmitter transmits the frame using an802.11 or a LTE protocol. In one or more embodiments, the control modulestops, delays or modifies the transmission of the frame based ondetection of a transmission from a third device. In one or moreembodiments, the control module determines whether to maintain, stop,delay or modify the transmission of the frame based on a priority of adetected transmission from a third device. In one or more embodiments,the detector determines the priority based on at least one or more of:content, message length, duration, a most recent transmission of thethird device, or battery status associated with the transmission fromthe third device. In one or more embodiments, the detector detects thatthe feedback includes a sample of the transmission, or includesinformation based on a LLR or decoded bits from the transmission. In oneor more embodiments, the control module updates at least one or more ofa MCS, code rate, code type, power, beamforming configuration, number ofspatial streams, bandwidth, or sub-band allocation of the transmissionresponsive to the feedback.

Referring to FIG. 2A, one or more embodiments of a system for in-bandfull-duplex operation is depicted. In brief overview, the systemincludes, in one or more embodiments, a device 103 operating within afrequency band of a WLAN environment that includes one or more WLANdevices 102. The device 103 includes one or more of: a detector 222, atransmitter 224, a receiver 223, a scheduler 221, a feedback unit 232,or a control module 233, in one or more embodiments. In variousembodiments, one or more of these elements or modules is combined intofewer elements, or includes one or more submodules. Each of theseelements, modules and/or submodules is implemented in hardware, or acombination of hardware and software, in one or more embodiments. Forinstance, each of these elements, modules and/or submodules optionallyor potentially includes one or more applications, programs, libraries,scripts, tasks, services, processes or any type and form of executableinstructions executing on hardware of the device 103, in one or moreembodiments. The hardware includes one or more of circuitry and/or aprocessor, for example, as described above in connection with at least1B and 1C, in one or more embodiments.

Although certain portions of the disclosure refer to LTE and/or WLAN (or802.11) communications and devices, such as licensed-assisted access(LLA) LTE or 802.11 ax, these references are merely for illustration andnot intended to be limiting in any way. For example, in-band full-duplexand/or half-duplex operation could occur and/or co-exist between anytype of devices, between devices using different communicationsprotocols, between devices using differing modulation techniques and/orhaving differing capabilities, and/or include communications between adevice capable of communicating in a full-duplex protocol with anotherdevice communicating in a half-duplex protocol.

Referring again to FIG. 2A, in one or more embodiments, the device 103includes a transmitter 224 and/or a receiver 223 designed, built and/orimplemented to respectively transmit and receive any type or form ofmessages or frames within a first frequency band or across differentfrequency bands. In one or more embodiments, the transmitter 224 andreceiver 223 operate in full-duplex (e.g., within a first frequencyband) and/or half-duplex modes, in communication with another device103, 102. In one or more embodiments, uplink and downlink transmissionsof devices in a system are scheduled independently. In one or moreembodiments, uplink and downlink transmissions of devices 103, 102 in asystem are tightly coupled or coordinated to increase system capacity,for example if some of the devices 103, 102 are full-duplex capable.Referring to FIG. 2B, for example, schematic diagrams of embodiments ofin-band operation is depicted. In-band full-duplex operation on the samefrequency band is sometimes considered ideal when device A istransmitting to device B and device B is transmitting to device A, inone or more embodiments. In this scenario, as illustrated in Case 1 ofFIG. 2B, device A receives interference from its own transmission, anddevice B receives interference from its own transmission, in one or moreembodiments. Thus, devices A and B each performs self-interferencecancellation (e.g., based on knowledge of each device's owntransmission), so that each device is able to simultaneously transmitand receive in one or more embodiments. This configuration potentiallydoubles the capacity of the system, by allowing simultaneous orconcurrent bi-directional communication on the same spectrum (samefrequency band), in one or more embodiments.

Referring now to Case 2 of FIG. 2B, device A performs self-interferencecancellation since it is the source of its own interference, in one ormore embodiments. Device B is however interfered with by device C'stransmission, which is unknown to device B in one or more embodiments.There are solutions for device B to reduce the effect of theinterference from device C, which for example potentially involvesadditional antennas at device B, spatial beamforming, and/or messaging(e.g., at the expense of overhead) between device, in one or moreembodiments. Some of these solutions do not completely eliminate theinterference at device B, so Case 1 is sometimes preferred over Case 2in one or more embodiments. Frequency symmetric scheduling is ascheduling method to make full or efficient use of the frequency band(s)in Case 1, in one or more embodiments. The term “symmetric” refers tomatching uplink and downlink frequency-domain scheduling, in one or moreembodiments.

Referring now to FIG. 2C, a schematic diagram of one embodiment ofin-band operation is depicted. The schematic diagram illustratesfrequency symmetric scheduling for in-band full-duplex devices as wellas half-duplex devices, in one or more embodiments. In one or moreembodiments, device A is an access point or base station, and devices B,C, D and E are devices in communication with device A, for example.Devices A, B and C are full duplex capable, and devices D and E are not,in one or more embodiments. In order to effectively utilize full-duplexcapability among the devices, device A schedules device B on a firstfrequency band for downlink and uplink transmissions. A similarlyschedules device C on a second frequency band for downlink and uplinktransmissions in one or more embodiments. In one or more embodiments, Aschedules unidirectional transmission for non-full duplex devices, e.g.,the third frequency band is assigned for downlink transmission to deviceD and channel component (1) is left unassigned, while the fourth band isassigned for uplink transmission from device E and channel component (2)is left unassigned. In one or more embodiments, if device D is capableof interference cancellation, it is possible to assign a device otherthan device D to transmit using channel component (1). Similarly, ifdevice E is capable of interference cancellation, device A can perform asimultaneous downlink transmission to a device other than device Eutilizing channel component (2).

In in-band full-duplex operation, two devices 103 maintain abi-directional link using a common spectrum (frequency band) in bothdirections in one or more embodiments. Using the bi-directional link (inwhich a device A transmits to a device B, and device B transmits todevice A), one or both of devices A and B perform self-interferencecancellation in one or more embodiments. Referring now to Case 2 of FIG.2B, for instance, if device C rather than device B transmits to device Aas illustrated, device A is able to perform self-interferencecancellation in one or more embodiments. However, device B cannotperform cancellation of the interference from C (e.g., because theinterference from device C cannot be easily characterized at device B bydevice B), in one or more embodiments. Thus, in one or more embodiments,restricting full-duplex to only bi-directional links potentially lowerssystem capacity when traffic is not symmetric.

In one or more embodiments, this disclosure provides solutions forcancellation of interference for the case of full-duplex operation withasymmetric transmissions. These solutions enable interferencecancellation in in-band full-duplex operation in one or moreembodiments. By way of illustration, and in one or more embodiments,device A transmits to device B, while device C simultaneously transmitsto device A (e.g., on same frequency band). Device A performsself-interference cancellation, so that A is able to transmit andreceive simultaneously (with no or reduced interference from device A'stransmissions). Device B receives a desired signal from device A, andalso interference from device C in one or more embodiments. B performsinterference cancellation on the C-to-B signal by using spatialcancellation, and/or physical antennasteering/reconfiguration/selection, in one or more embodiments. Forinstance, device B learns the spatial signature of the C-to-B link, anddesigns receive vectors that null or reduce the interference power fromdevice C in one or more embodiments. In one or more embodiments, deviceC selects transmit beamforming vectors, or an antenna configuration,such that the interference imparted to device B is reduced orsubstantially eliminated. In one or more embodiments, device A learnsfrom the channels (e.g., B-to-C, possibly also A-to-B and C-to-A) anddesigns transmit beamforming vectors for the A-to-B link and C-to-Alink, such that device B is able to achieve a highsignal-to-interference-plus-noise ratio (SINR). In one or moreembodiments, device B selects an antenna (or an antenna subset) that isimplemented and/or designed to receive minimal interference from deviceC.

In one or more aspects, this disclosure describes device-assisted uplinkdetection via in-band full-duplex operation. This increases the systemand/or throughput capacity even further for in-band full-duplex systemsbeyond bi-directional links while using the same spectrum in bothdirections, in one or more embodiments. This solution uses or sharesinformation of observed interference in a full duplex system, in one ormore embodiments. For example, not only does device B attempt to cancelthe interference from the C-to-B link, device B is able to extractinformation (from the C-to-B signal) on C's transmission, andpotentially forward that information to device A (e.g., as shown in Case3 of FIG. 2B), to assist device A in decoding device C's transmission inone or more embodiments.

In one or more embodiments, device B provides macro-diversity to deviceA, e.g., effectively provides (or lends) one or more additionalantenna(s) to device A for decoding the C-to-A transmission. Forexample, and in one or more embodiments, the link to carry thisforwarded information is in-band, e.g., using the same frequency as theother two desired transmissions, or alternatively on a separate band. Inone or more embodiments, device B is able to forward (via the link)device B's received samples to device A. Device A knows what ittransmitted to device B, and so can remove that part of the signal fromsamples received from B, in one or more embodiments. The remainingportion is the C-to-B signal, from which device A is able to obtainextra information on device C's transmission, in one or moreembodiments. In one or more embodiments, device B jointly decodes theA-to-B and C-to-B transmissions, and includes LLR information on deviceC's transmission in the information forwarded to device A. The LLRinformation is input into, or utilized by device A's decoder in one ormore embodiments (e.g., for decoding the C-to-A transmission). In one ormore embodiments, device B performs receive filtering to (spatially)separate the A-to-B and C-to-B transmissions. In one or moreembodiments, device B forwards (e.g., only) the samples corresponding tothe C-to-B transmission or link to device A. These are merely some ofthe techniques for supporting full-duplex operation, and any two or moreof the techniques described in this disclosure are combinable in one ormore embodiments of the present systems and methods.

In one or more embodiments, the present systems and methods leverage onin-band full-duplex for efficient and/or effective collision avoidanceand/or detection. In one or more embodiments, collisions arefundamentally difficult to avoid in half duplex systems, because when adevice is transmitting, the device is not capable of listening for othersimultaneous transmissions or feedback from an intended receiver. Withfull duplex, a transmitting device 103 is able to receive while it istransmitting a packet or message, in one or more embodiments. Thetransmitting device 103 is capable of listening for another simultaneoustransmission on the air, e.g., a collision, in one or more embodiments.The transmitting device 103 is capable of listening for feedback from anintended receiving device 103, in one or more embodiments. Therefore,when applied to various types of devices, a transmitting device 103 isable to listen for simultaneous transmission and operate according to aprotocol for coexistence of different types of devices (e.g., LLA LTEand WLAN devices sharing the same frequency band), or to make one typeof devices (e.g., WLAN devices) operate more efficiently and morecompetitively with another type (e.g., LLA LTE devices), in one or moreembodiments.

By way of illustration, and in one or more embodiments, a receivingdevice 103 transmits (e.g., via the transmitter 224) feedback, whichincludes a confirmation message, to a transmitting device 103 with anongoing transmission. In one or more embodiments, the device 103includes a feedback unit 232, implemented to provide or share feedbackor other information (e.g., via a confirmation message, collisionmessage, channel/transmission information, interference information,samples of received transmission) to another device 103. In one or moreembodiments, the feedback unit 232 of the receiving device 103 transmitsthe feedback or a confirmation message after successfully decoding apreamble from the ongoing transmission. For example, the receivingdevice 103 detects and/or decodes the beginning of the transmission,e.g., the first 20 milliseconds of the transmission, which include thepreamble or a portion of the preamble, to determine whether a successfuldecode has been performed.

Referring again to FIG. 2A, and in one or more embodiments, the device103 includes a detector 222 implemented to detect a preamble of atransmission, detect additional transmission(s) in the frequency band,and/or to detect a collision. In one or more embodiments, the detector222 interoperates with the feedback unit 232 to produce an appropriatefeedback to another device (e.g., the transmitting device 103). In oneor more embodiments, the transmitting device 103 includes a scheduler221 configured to determine a time to begin a transmission,stop/delay/hold the transmission, determine a frequency band for atransmission (e.g., forwarding interference/channel information, acapabilities announcement, a collision message)) and/or determine a timeto continue the transmission or to restart the transmission. In one ormore embodiments, the scheduler 221 of the transmitting device 103stops, delays or holds its transmission unless or until the transmittingdevice 103 receives the confirmation message or feedback.

In one or more embodiments, the confirmation message is not sent if thereceiving device 103 detects a collision. In one or more embodiments,the confirmation message is not sent if the receiving device 103 isunable to decode the preamble (e.g., due to high interference fromself-interference and/or another transmission, for instance, from athird or hidden node). In one or more embodiments, the receiving device103 sends a confirmation message periodically during the frame ortransmission, e.g., at intervals of each millisecond. Alternatively, andin one or more embodiments, the feedback unit 232 of the receivingdevice 103 opportunistically sends a “stop/delay/hold” message(sometimes referred to as a collision message) with respect to thetransmission if the receiving device 103 detects or encounters (via thedetector 222) an unsuccessful decoding during the transmission.

In one or more embodiments, the feedback unit 232 conveys or relayscollision detection information to other devices or nodes after thepacket transmission which is being affected, and/or which is affectinganother transmission, ends. In one or more embodiments, the feedbackunit 232 is implemented to mitigate or reduce possible collision(s)during the transmission of packet(s) or frame(s). In one or moreembodiments, whenever a receiver device 103 (e.g., an access point,intended receiver) detects a collision (e.g., simultaneous reception ofmultiple packets), the feedback unit 232 transmits or broadcasts aspecial collision message. In one or more embodiments, a protocol couldbe implemented so that all devices currently transmitting to the senderof the collision message, end their transmission(s). In one or moreembodiments, the collision message specifies or identifies the device(s)that are to end/postpone/delay/hold transmission (e.g., to allow onetransmission, such as a transmission with the most power or priority, tocontinue or proceed without interference). In one or more embodiments,this enables collisions to be resolved quickly, instead of havingcollisions to be unresolved until the end of the frame transmission(e.g., when no ACK is received). In one or more embodiments, thismechanism is enabled or disabled based at least in part on network load(e.g., the mechanism is disabled when the network is not busy).

In one or more embodiments, the feedback unit 232 sends feedback toperform collision avoidance based on priority and/or quality of service(QoS) accorded to certain packets or frames. In some other embodiments,all packets or frames are treated equally for collision detection andmitigation. In one or more embodiments, a transmitting device 103continues to receive messages while maintaining a transmission. In oneor more embodiments, if during the transmission, the currenttransmitting device 103 decodes a packet from another transmission(e.g., not from a device intended to receive the transmitting device'stransmission), a control module 233 and/or scheduler 221 of thetransmitting device 103 determines to end, delay, or modify (e.g.,reduce power) the current transmission.

In one or more embodiments, the control module of a device 103 isdesigned and/or implemented to modify one or more transmissionparameters of the host device 103, for example, based on receivedfeedback, detection of an additional transmission on the air, and/orresults from decoding a received transmission. In one or moreembodiments, a protocol assigns different priorities to differenttransmissions, e.g., control messages have top or preferred priority. Ifthe transmitting device 103 decodes a preamble of another frame ortransmission with a higher priority, the control module 233 and/orscheduler 221 determines that the current transmission is to back off,terminate or be delayed.

In one or more embodiments, priority-based or QoS-based control of atransmission allows one or more higher priority messages to betransmitted in lieu or instead of lower priority messages on anas-needed basis. For instance, in one or more embodiments, prioritydepends on content of the message, and/or other parameters, such as:message length, an amount of time since a last successful transmission.In one or more embodiments, the control module 233 determines a batterystatus or power supply level (e.g., low power devices generally allowedto proceed with a transmission) to determine a priority for thecorresponding device. In one or more embodiments, a high or preferredpriority is assigned to a new device and/or a new connection. In one ormore embodiments, a higher or preferred priority is assigned to aspecific type of device relative to another type of device.

In one or more embodiments, methods and systems for full-duplexoperation include the aspect of sending real time feedback to atransmitting device 103. In one or more embodiments, real time feedbackis leveraged to improve transmission throughput. In one or moreembodiments, full-duplex allows devices to send real-time feedback,without interrupting an ongoing transmission. On the other hand, to sendfeedback, half-duplex devices would have to end or delay a current datatransmission, switch between transmitter and receiver modes, and thentransmit a feedback frame in reverse direction relative to the currentdata transmission, in one or more embodiments. In one or moreembodiments, a full-duplex method for feedback is much more efficientthan half-duplex operation, and allows for on-the-fly adjustment oftransmission parameters in response to received feedback.

In one or more embodiments, information is fed back in real time fromthe receiving device to the transmitting device. The informationincludes received samples (e.g., possibly quantized, time and/orfrequency-domain samples), LLRs (possibly quantized), function of LLRsand decoded bits (e.g., a receiving device computes one or more paritieson decoded bits and feeds back the computed parities), and/or indices ofbits that have weak LLRs, success/failure of each codeword, in one ormore embodiments. In one or more embodiments, the information includessignal-to-noise ratio (SNR) or SINR (e.g., instantaneous or in realtime), and possibly per tone or frequency. In one or more embodiments,the information includes channel estimation information (in time and/orfrequency-domain, possibly quantized, possibly for multiple inputmultiple output—MIMO). In one or more embodiments, the informationincludes an estimate of interfering signals, e.g., interferencecovariance information.

In one or more embodiments, in response to the received feedback, thetransmitting device 103 adjusts one or more of: MCS, code rate, codetype, specific coding and/or interleaver pattern, per-tone powerloading, spatial mapping matrix (e.g., a beamforming matrix), OrthogonalFrequency-Division Multiple Access (OFDMA) sub-band allocation, numberof spatial streams, bandwidth, transmission power, etc. In one or moreembodiments, a device 103 sends real-time feedback (e.g., forinstantaneous MCS adjustment, instantaneous ACK, etc.) on a separatefrequency (e.g., in FDD system). However, that approach is probably lessefficient and is potentially unfeasible due to bandwidth limitation, inone or more embodiments. In one or more embodiments, some uses ofreal-time feedback proposed here involve feeding back large amounts ofinformation and is reasonable if the feedback is performed on a separatefrequency.

In one or more embodiments, the use of real-time feedback, such as MCSfeedback, eliminates or reduces a preference for a conservative MCS,e.g., to be selected initially for a transmission. In one or moreembodiments, a transmitting device 103 initially chooses or selects anaggressive MCS, e.g., with the assumption that there is little or nointerference on the air. If interference arrives or appears, a device103 receiving the transmission of the transmitting device 103 providesreal-time feedback to indicate or describe the interference, in one ormore embodiments. Responsive to the real-time feedback, the transmittingdevice 103 downgrades or reduces the MCS for the ongoing transmission(or for a retransmission) in one or more embodiments. In one or moreembodiments, for example, a transmitting device 103 begins transmissionat a low transmit power, and increases the transmit power if appropriate(e.g., responsive to real time feedback from the receiving device 103).

In one or more embodiments, real-time feedback is used when appropriateor worthwhile (e.g., from a power consumption or overhead perspective).For example, both sides of the full-duplex transmission link should takeinto account additional power consumed by the feedback link, in one ormore embodiments. The system is able to enable feedback when there is anet benefit, in one or more embodiments. In one or more embodiments, onedevice 103 is able to inform the other if the device 103 does not wantto currently use or support a feedback link. In one or more embodiments,a device 103 is able to combine (e.g. multiplex) real-time feedback withreverse-direction data to transmit to the other device 103. In one ormore embodiments, a device 103 is able to combine forward-direction datawith real-time feedback describing a reverse direction data link.

In one or more embodiments, such as in a device using an 802.11 orWiFi-based protocol for communications, certain changes are applied tothe protocol features to support in-band full-duplex operation (e.g.,between at least two devices). For example, and in one or moreembodiments, a protocol change is applied to enable a device B totransmit back to a device A while device A is transmitting to device B,in full-duplex operation. In one or more embodiments, device A beginstransmitting a frame to device B. Device B decodes a preamble of theA-to-B transmission, and determines a length of the corresponding A-to-Bframe in one or more embodiments. If device A is full duplex capable(e.g., as communicated during capabilities exchange or handshake, e.g.,at time of association of the devices), device B is allowed to starttransmitting a frame to device A, in one or more embodiments. In one ormore embodiments, the B-to-A frame is implemented to end no later thanthe time at which the A-to-B frame ends.

In one or more embodiments, the present systems and methods imposes orenforces one or more rules on the B-to-A frame. For instance, and in oneor more embodiments, the B-to-A frame transmission is sent at a reducedpower and/or MCS (e.g., relative to the A-to-B frame transmission). Inone or more embodiments, device B is able to select or choose a MCSand/or transmit power so that the B-to-A frame transmission ends at orroughly around the same time as the end of the A-to-B transmission. Inone or more embodiments, device B (e.g., in coordination with device A)is able to stretch out or extend the B-to-A frame or transmission to endat or roughly around the same time as the end of the A-to-Btransmission, e.g., for improved utilization of the bandwidth orchannel. In one or more embodiments, the airtime is reserved (e.g., forthe full-duplex transmission, including the B-to-A frame transmission),since the A-to-B frame transmission is already underway. Thus, collisionfrom transmissions of other devices could be avoided or prevented, inone or more embodiments. In one or more embodiments, selecting arelatively low link (or low MCS) for the B-to-A frame transmission(e.g., reducing self-interference at device A) allows device A todeactivate, or to reduce the accuracy or extent of device A'sself-interference cancellation circuit.

In one or more embodiments, device A includes or incorporatesinformation into an A-to-B preamble to indicate that a B-to-A (orreverse direction) transmission is allowed or supported (during, or atthe same time as the ongoing A-to-B or forward direction transmission).In one or more embodiments, the included information, or the support forthe B-to-A transmission, is subject to certain constraints (e.g., amaximum or threshold MCS for the B-to-A transmission). In one or moreembodiments, device A is able to reduce the MCS of the A-to-Btransmission due to, or based on device A's knowledge of device B'sself-interference capability, and/or in anticipation of device B sendinga simultaneous or concurrent B-to-A frame. By way of non-limitingillustration, the devices are able to coordinate communication using abi-directional request to send (RTS)/clear to send (CTS) mechanism, inone or more embodiments. In one or more embodiments, a device 103 isable to indicate in a RTS and/or CTS message to the other device 103that traffic is going to be sent in both directions. For instance,device A transmits a RTS message and device B responds with a messagewhich includes a CTS and/or a RTS message (e.g., to indicate that A isclear to send, and also to request to proceed with a B-to-Atransmission).

In one or more embodiments, two or more devices 103 are able to performa full-duplex capability exchange (e.g., via their respective feedbackunits 232), e.g., at time of association and/or prior to datatransmission. In one or more embodiments, a device 103 is able to send,broadcast or otherwise announce the device's capabilities, e.g., priorto data transmission. In one or more embodiments, the capabilityexchange or announcement includes one or more of: whether or not thedevice 103 is full duplex capable, the level of accuracy or extent ofself-interference cancellation of which the device 103 is capable, apower range within which the device 103 operates or is capable of forperforming full duplex operation (e.g., a threshold or floor receiverpower level at which the device is capable of in performing full duplexoperation), power cost to the device 103 to perform full duplexoperation, a MCS threshold or limit supported by the device forreceiving a frame while performing full duplex operation, or a limit tothe number of spatial streams that the device 103 is capable ofreceiving while in full duplex operation. In one or more embodiments,the capability exchange or announcement is leveraged for situations inwhich data transmission in two directions are asymmetric. In one or moreembodiments, the capability exchange or announcement allows balancingbetween devices, for example allowing a device 103 to reduce atransmission power if the device 103 is transmitting less data than thetransmission in the other direction (e.g., data in the downward stream).

Referring now to FIG. 2D, one or more embodiments of a method for LTE-Uand WLAN coexistence is depicted. In one or more embodiments, the methodincludes transmitting, by a first device 103, a frame to a second devicewirelessly within a first frequency band (operation 201). The firstdevice 103 determines whether to maintain, stop, delay or modify thetransmission of the frame based on detection of a transmission from athird device (operation 203). The second device 103 receives the framefrom the first device 103 transmitted within the first frequency band(operation 205). The second device 103 sends, while the transmission ofthe frame is ongoing, feedback to the first device 103 within the firstfrequency band, the feedback in response to the ongoing transmission ofthe frame (operation 207). The first device 103 detects, while thetransmission of the frame is ongoing, the feedback from the seconddevice 103 within the first frequency band (operation 209). The firstdevice 103 determines, responsive to the feedback, whether to stop theongoing transmission of the frame or to update a transmission parameterfor the ongoing transmission within the first frequency band (operation211).

Referring now to operation 201, and in one or more embodiments, a firstdevice 103 transmits a frame to a second device wirelessly within afirst frequency band. In one or more embodiments, the first device isone of a WLAN device or a LTE device, and the second device is the otherof the WLAN device or the LTE device. In one or more embodiments, boththe first and the second devices 103 are of the same type (e.g., eitherWLAN or LTE devices). In one or more embodiments, the first and/orsecond devices employs a RTS/CTS mechanism to setup a bidirectionalcommunications channel, e.g., in-band full-duplex communications. Forexample, the first device 103 transmits a RTS message and device Bresponds with a message which includes a CTS and/or a RTS message, asdiscussed above in connection with at least FIG. 2A. In one or moreembodiments, the first and/or second devices engages in a full-duplexcapability exchange (e.g., via their respective feedback units 232), forexample as discussed above in connection with at least FIG. 2A. Thefirst device 103 selects transmission parameters (e.g., MCS,transmission power) for the transmission of the frame, e.g., in responseto the RTS/CTS exchange or the full-duplex capability exchange. Forexample, the first device 103 selects a more aggressive initial MCS forthe transmission, e.g., based on the enabling of real time feedback forthe full-duplex channel.

The first device 103 transmits, via a transmitter 224 of the firstdevice, the frame in one or more embodiments. The transmission of theframe is sometimes simply referred to as a transmission. The transmitter224 wirelessly transmits the frame to the second device 103 within afirst frequency band in one or more embodiments. In one or moreembodiments, the transmitter 224 transmits the frame using an 802.11 ora LTE protocol. In one or more embodiments, the first device 103receives (e.g., via a receiver 223) a transmission from the seconddevice 103 in accordance with the full-duplex operation, thetransmission including data, control information and/or feedback (e.g.,regarding the ongoing transmission). The first device 103 performsself-interference cancellation in one or more embodiments, for exampleas discussed above in connection with at least FIGS. 2A and 2B. In oneor more embodiments, the first and/or second devices adapts theirtransmission configuration based on any of the techniques discussedabove in connection with at least FIGS. 2A-2C.

Referring now to operation 203, and in one or more embodiments, thefirst device 103 determines whether to maintain, stop, delay or modifythe transmission of the frame based on detection of a transmission froma third device. In one or more embodiments, a detector 222 of the firstdevice 103 detects for a transmission from the second device 103 (e.g.,for feedback) or any other devices (e.g., indicating a possiblecollision). In one or more embodiments, the detector 222 listens forsimultaneous transmission so that the first device 103 operates oradapts according to a protocol for coexistence of different types ofdevices.

The detector 222 detects a transmission from another (e.g., a third)device in one or more embodiments. In one or more embodiments, thecontrol module 233 of the first device 103 determines whether tomaintain, stop, delay or modify the transmission of the frame based on,or in response to the detection. In one or more embodiments, thedetector 222 detects a priority of the transmission from the otherdevice, e.g., based on the detected transmission. The detector 222determines the priority based on at least one or more of: content,message length, duration, a most recent transmission, or battery statusassociated with the transmission from the third device. The controlmodule 233 determines whether to maintain, stop, delay or modify thetransmission of the frame based at least in part on a priority of thetransmission from the other device, in one or more embodiments. Thecontrol module 233 makes the determination based on the priority of thetransmission from the other device relative to that of the transmissionfrom the first device 103 in one or more embodiments.

Referring now to operation 205, and in one or more embodiments, thesecond device 103 receives the frame from the first device 103transmitted within the first frequency band. The second device 103receives (e.g., via a receiver 223 of the second device 103) thewireless transmission from the first device 103 in one or moreembodiments. A detector 222 of the second device 103 processes orotherwise decodes a portion (e.g., first or initial portion) of thereceived transmission or frame in one or more embodiments. For example,the second device 103 detects and/or decodes the beginning of thetransmission, e.g., the first 20 milliseconds of the transmission, todetermine whether a successful decode has been performed. In one or moreembodiments, the detector 222 decodes a preamble of the frame while thetransmission is ongoing. A feedback unit 232 of the second device 103determines or decides whether to send feedback to the first device 103,e.g., based on the decoding, in one or more embodiments.

Referring now to operation 207, and in one or more embodiments, thesecond device 103 generates and/or sends, while the transmission of theframe is ongoing, feedback to the first device 103 within the firstfrequency band. The second device 103 sends real time feedback to thefirst device 103 while the transmission of the frame is ongoing in oneor more embodiments. In one or more embodiments, the second device 103generates, provides, transmits and/or sends the feedback in response tothe ongoing transmission of the frame, and/or any other detectedtransmission in the channel. For instance, in one or more embodiments,the second device 103 sends feedback in the form of a confirmationmessage to indicate that the receiving device is able to successfullydecode the received transmission (e.g., and the absence of a collision).In one or more embodiments, a confirmation message is not sent if thesecond device 103 detects a collision. In one or more embodiments, thetransmitter 224 of the second device is implemented to transmit thefeedback (e.g., a confirmation message) using an 802.11 or a LTEprotocol.

In one or more embodiments, the second device sends a confirmationmessage upon, or based on a successful decode of a preamble or otherportion of the received transmission. In one or more embodiments, thesecond device sends a confirmation message upon, or based on an absenceof any detected collision, or interference that affected the decoding ofthe transmission. In one or more embodiments, the confirmation messageis not sent if the second or receiving device 103 is unable to decodethe preamble (e.g., due to high interference from self-interferenceand/or another transmission, for instance, from a third or hidden node.In one or more embodiments, the second device sends the feedback to thefirst device periodically or at regular intervals while the transmissionof the frame is ongoing. For example, and in one or more embodiments,the second device sends a confirmation message based on successfulreceipt and/or decoding of the transmission at a predetermined interval(e.g., of 1 millisecond). Alternatively, and in one or more embodiments,the feedback unit 232 of the receiving device 103 opportunisticallysends a “stop/delay/hold” message (sometimes referred to as a collisionmessage) with respect to the transmission if the receiving device 103detects or encounters (via the detector 222) an unsuccessful decodingduring the transmission.

In one or more embodiments, the second device includes or piggybacks thefeedback with a transmission of data to the first device 103. In one ormore embodiments, the feedback unit 232 of the second device 103 sendsfeedback to perform collision avoidance based on priority and/or qualityof service accorded to certain packets or frames (e.g., a controlmessage), for example as discussed above in connection with at leastFIG. 2A. For instance, in one or more embodiments, the feedback unit 232determines the priority based on content of the transmission, and/orother parameters, such as: message length, an amount of time since alast successful transmission. In one or more embodiments, the feedbackunit 232 determines a battery status or power supply level (e.g., lowpower devices generally allowed to proceed with a transmission) todetermine a priority for the corresponding device. In one or moreembodiments, a high or preferred priority is assigned to a new deviceand/or a new connection. In one or more embodiments, a higher orpreferred priority is assigned to a specific type of device relative toanother type of device.

In one or more embodiments, the second device 103 sends feedback thatincludes a sample of the received transmission, and/or includesinformation based on a log likelihood ratio (LLR) or decoded bits fromthe received transmission. For example, the second device 103 sendsfeedback that includes received samples (e.g., possibly quantized, timeand/or frequency-domain samples), LLRs (possibly quantized), function ofLLRs and decoded bits (e.g., a receiving device computes one or moreparities on decoded bits and feeds back the computed parities), and/orindices of bits that have weak LLRs, success/failure of each codeword,in one or more embodiments. In one or more embodiments, the feedbackincludes signal-to-noise ratio (SNR) or SINR (e.g., instantaneous or inreal time), and possibly per tone or frequency. In one or moreembodiments, the feedback includes channel estimation information (intime and/or frequency-domain, possibly quantized, possibly for multipleinput multiple output—MIMO). In one or more embodiments, the feedbackincludes an estimate of interfering signals, e.g., interferencecovariance information. In one or more embodiments, for example when theamount of information in the feedback in substantial, the second device103 sends feedback on a separate frequency or frequency band, e.g.,other than the first frequency band.

In one or more embodiments, a detector 222 of the second device 103detects, while the transmission is ongoing, a transmission from aanother (e.g., a third) device within the first frequency band. Thesecond device sends the feedback (e.g., a collision message) based onthe detected transmission from another device, for example as discussedabove in connection with at least FIG. 2A. In one or more embodiments,the second device 103 sends the feedback which includes a messagetransmitted to one or more devices, the message identifying, instructingor requesting at least one of the one or more devices to stop, halt orpostpone transmission. In one or more embodiments, the second device 103sends the message based on a determination of a priority of thetransmission from the other device, e.g., relative to a priority of thetransmission from the first device. For instance, and in one or moreembodiments, the message instructs the first device 103 or the otherdevice to stop the corresponding transmission, based on whichtransmission has a higher priority, such that the lower prioritytransmission should back off. For example, and in one or moreembodiments, the collision message specifies or identifies the device(s)that are to end/postpone/delay/hold transmission, to allow onetransmission, such as a transmission with the most power or priority, tocontinue or proceed without interference.

Referring now to operation 209, and in one or more embodiments, thefirst device 103 detects, while the transmission of the frame isongoing, the feedback from the second device 103 within the firstfrequency band. A receiver 223 of the first device 103 receives thefeedback in one or more embodiments. The detector 222 of the firstdevice 103 detects, while the transmission of the frame is ongoing, thefeedback from the second device in one or more embodiments. The detector222 detects that the feedback is in response to the ongoing transmissionof the frame, or in response to a collision, in one or more embodiments.The detector detects or otherwise determines that the feedback includesat least a sample of the transmission, or includes information based ona LLR or decoded bits from the transmission, as discussed above and alsoin connection with at least FIG. 2A.

Referring now to operation 211, and in one or more embodiments, thefirst device 103 determines, responsive to the feedback, whether to stopthe ongoing transmission of the frame or to update a transmissionparameter for the ongoing transmission within the first frequency band.A control module 233 of the first device determines, responsive to thefeedback, whether to modify or suspend the ongoing transmission of theframe within the first frequency band, in one or more embodiments. Inone or more embodiments, the control module 233 is implemented todetermine whether to update one or more parameters for the transmissionresponsive to the received feedback. In one or more embodiments, thecontrol module 233 updates at least one or more of a MCS, code rate,code type (e.g., specific coding and/or interleaver pattern), power(e.g. per-tone power loading), beamforming configuration (e.g., spatialmapping matrix, beamforming matric), number of spatial streams,bandwidth, or OFDMA sub-band allocation of the transmission, responsiveto the feedback and the determination, for example as discussed above inconnection with at least FIG. 2A.

By way of illustration, and in one or more embodiments, the first device103 initially chooses or selects an aggressive MCS, e.g., with theassumption that there is little or no interference on the air. Ifinterference arrives or appears, the second device 103 providesreal-time feedback to indicate or describe the interference, in one ormore embodiments. Responsive to the real-time feedback, the first device103 downgrades or reduces the MCS for the ongoing transmission (or for aretransmission) in one or more embodiments. In one or more embodiments,for example, the first device 103 begins transmission at a low transmitpower, and increases the transmit power responsive to real time feedbackfrom the second device 103.

In one or more embodiments, the control module 233 determines to stop,delay or modify the transmission of the frame based on detection (by thefirst and/or second device) of a transmission from another (e.g., athird) device. In one or more embodiments, the feedback includes aninstruction to the control module 233 to stop, delay or modify thetransmission of the frame based on detection. In one or moreembodiments, the control module 233 determines whether to maintain,stop, delay or modify the transmission of the frame based on a priorityof a detected transmission from the other device. In one or moreembodiments, the feedback includes an indication of the priority of thedetected transmission from the other device. In one or more embodiments,the priority is based on at least one or more of: content, messagelength, or duration of the transmission of the other device, a mostrecent transmission of the other device if any (e.g., if this is a firsttransmission from the other device, or if the other device has recentlytransmitted a frame successfully or attempted to do so unsuccessfully),or a battery status or remaining power level associated with thetransmission from the other device.

In one or more embodiments, the first device updates, for the ongoingtransmission, at least one or more of the MCS, transmission code rate,transmission code type (e.g., modulation scheme), transmission power,beamforming configuration, number of spatial streams used, bandwidthallocation or use, or sub-band allocation, responsive to the feedback.In one or more embodiments, the first device 103 stops or postpones thetransmission. In one or more embodiments, the first device 103identifies, selects or assigns, for a postponed transmission, apostponed transmission of a remainder of the frame (e.g., theuntransmitted portion of the frame), or for a retransmission of theframe, a MCS, transmission code rate, transmission code type,transmission power, beamforming configuration, number of spatial streamsused, bandwidth allocation or use, or sub-band allocation, responsive tothe feedback.

Although the disclosure might reference one or more “users”, such“users” can refer to user-associated devices, for example, consistentwith the terms “user” and “multi-user” typically used in the context ofa MU-MIMO environment. Although examples of communications systemsdescribed above sometimes describe devices and/or access pointsoperating according to an IEEE 802.11, 3GPP or LTE standard, it shouldbe understood that embodiments of the systems and methods described canoperate according to other standards and use wireless communicationsdevices other than devices implemented as devices and base stations. Forexample, communication interfaces associated with cellular networks,satellite communications, vehicle communication networks, 802.11 andother non-802.11 wireless networks can utilize the systems and methodsdescribed herein to achieve improved overall capacity and/or linkquality without departing from the scope of the systems and methodsdescribed herein.

It should be noted that certain passages of this disclosure canreference terms such as “first” and “second” in connection with devices,frames, etc., for purposes of identifying or differentiating one fromanother or from others. These terms are not intended to merely relateentities (e.g., a first device and a second device) temporally oraccording to a sequence, although in some cases, these entities caninclude such a relationship. Nor do these terms limit the number ofpossible entities (e.g., devices) that can operate within a system orenvironment.

It should be understood that the systems described above can providemultiple ones of any or each of those components and these componentscan be provided on either a standalone machine or, in some embodiments,on multiple machines in a distributed system. In addition, the systemsand methods described above can be provided as one or morecomputer-readable programs or executable instructions embodied on or inone or more articles of manufacture. The article of manufacture can be afloppy disk, a hard disk, a CD-ROM, a flash memory card, a PROM, a RAM,a ROM, or a magnetic tape. In general, the computer-readable programscan be implemented in any programming language, such as LISP, PERL, C,C++, C#, PROLOG, or in any byte code language such as JAVA. The softwareprograms or executable instructions can be stored on or in one or morearticles of manufacture as object code.

While the foregoing written description of the methods and systemsenables one of ordinary skill to make and use various embodiments ofthese methods and systems, those of ordinary skill will understand andappreciate the existence of variations, combinations, and equivalents ofthe specific embodiment, method, and examples herein. The presentmethods and systems should therefore not be limited by the abovedescribed embodiments, methods, and examples, but by all embodiments andmethods within the scope and spirit of the disclosure.

We claim:
 1. A method for in-band full-duplex operation, the methodcomprising: transmitting, by a first device, a frame to a second devicewirelessly within a first frequency band; detecting, by the first devicewhile the transmission of the frame is ongoing, feedback from the seconddevice within the first frequency band, the feedback in response to theongoing transmission of the frame; and determining, by the first deviceresponsive to the feedback, whether to stop the ongoing transmission ofthe frame or to update a transmission parameter for the ongoingtransmission within the first frequency band.
 2. The method of claim 1,wherein the transmission of the frame and transmission of the feedbackboth use an 802.11 or a long term evolution (LTE) protocol.
 3. Themethod of claim 1, further comprising detecting, by the first device, atransmission from a third device, and determining to stop, delay ormodify the transmission of the frame based on the detection of thetransmission from the third device.
 4. The method of claim 1, furthercomprising detecting, by the first device, a transmission from a thirddevice, and determining whether to maintain, stop, delay or modify thetransmission of the frame based on a priority of the transmission fromthe third device.
 5. The method of claim 4, further comprisingdetermining, by the first device, the priority based on at least one ormore of: content, message length, duration, a most recent transmission,or battery status associated with the transmission from the thirddevice.
 6. The method of claim 1, wherein the feedback comprises asample of the transmission, or comprises information based on a loglikelihood ratio (LLR) or decoded bits from the transmission.
 7. Themethod of claim 1, further comprising updating, by the first device, atleast one or more of a modulation and coding scheme (MCS), code rate,code type, power, beamforming configuration, number of spatial streams,bandwidth, or sub-band allocation of the transmission responsive to thefeedback.
 8. A method for in-band full-duplex operation, the methodcomprising: receiving, by a first device, a frame from a second devicetransmitted wirelessly within a first frequency band; sending, by thefirst device while the transmission of the frame is ongoing, feedback tothe second device within the first frequency band, the feedback inresponse to the ongoing transmission of the frame, wherein the feedbackcomprises information indicating whether to stop the ongoingtransmission of the frame or to update a transmission parameter for theongoing transmission within the first frequency band.
 9. The method ofclaim 8, comprises detecting, while the transmission is ongoing, atransmission from a third device within the first frequency band, andsending the feedback based on the detected transmission from the thirddevice.
 10. The method of claim 8, wherein the first device is one of awireless local area network (WLAN) device or a long term evolution (LTE)device, and the second device is the other of the WLAN device or the LTEdevice.
 11. The method of claim 8, comprises decoding a preamble of theframe while the transmission is ongoing, and determining whether to sendthe feedback based on the decoding.
 12. The method of claim 8,comprising sending, by the first device, feedback to the second deviceat regular intervals while the transmission of the frame is ongoing. 13.The method of claim 8, wherein the feedback comprises a messagetransmitted to one or more devices, the message identifying at least oneof the one or more devices to stop transmission.
 14. A system forin-band full-duplex operation, the system comprising: a transmitter of afirst device, the transmitter configured to wirelessly transmit a frameto a second device within a first frequency band; a detector of thefirst device, the detector configured to detect, while the transmissionof the frame is ongoing, feedback from the second device within thefirst frequency band, the feedback in response to the ongoingtransmission of the frame; and a control module of the first device, thecontrol module configured to determine, responsive to the feedback,whether to modify or suspend the ongoing transmission of the framewithin the first frequency band.
 15. The system of claim 14, wherein thetransmitter is configured to transmit the frame using an 802.11 or along term evolution (LTE) protocol.
 16. The system of claim 14, whereinthe control module is configured to stop, delay or modify thetransmission of the frame based on detection of a transmission from athird device.
 17. The system of claim 14, wherein the control module isconfigured to determine whether to maintain, stop, delay or modify thetransmission of the frame based on a priority of a detected transmissionfrom a third device.
 18. The system of claim 17, wherein the detector isconfigured to determine the priority based on at least one or more of:content, message length, duration, a most recent transmission of thethird device, or battery status associated with the transmission fromthe third device.
 19. The system of claim 14, wherein the detector isconfigured to detect that the feedback comprises a sample of thetransmission, or comprises information based on a log likelihood ratio(LLR) or decoded bits from the transmission.
 20. The system of claim 14,wherein the control module is configured to update at least one or moreof a modulation and coding scheme (MCS), code rate, code type, power,beamforming configuration, number of spatial streams, bandwidth, orsub-band allocation of the transmission responsive to the feedback.